Difference between revisions of "Magnesium"

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[[File:Magnesium_ribbon.jpg|thumb|240px|Magnesium ribbon stored in mineral oil to prevent oxidation]]
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{{Infobox element
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'''Magnesium''' is an [[alkaline earth metal]] with the symbol Mg and atomic number 12. It is one of the most powerful [[reducing agent]]s available to the amateur chemist, even more so than [[zinc]]. However, it is impossible to plate magnesium out of an aqueous solution, and it is generally not feasible to recover the metal.
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<!-- top -->
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|image name=Magnesium_ribbon.jpg
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|image alt=
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|image size=200
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|image name comment=Magnesium ribbon stored in mineral oil to prevent oxidation
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|image name 2=
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|image alt 2=
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|image size 2=
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|image name 2 comment=
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<!-- General properties -->
 +
|name=Magnesium
 +
|symbol=Mg
 +
|pronounce=
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|pronounce ref=
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|pronounce comment=
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|pronounce 2=
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|alt name=
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|alt names=
 +
|allotropes=
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|appearance=Silvery-white
 +
<!-- Periodic table -->
 +
|above=[[Beryllium|Be]]
 +
|below=[[Calcium|Ca]]
 +
|left=[[Sodium]]
 +
|right=[[Aluminium]]
 +
|number=12
 +
|atomic mass=24.305
 +
|atomic mass 2=
 +
|atomic mass ref=
 +
|atomic mass comment=
 +
|series=
 +
|series ref=
 +
|series comment=
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|series color=
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|group=2
 +
|group ref=
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|group comment= 2 (alkaline earth metals)
 +
|period=3
 +
|period ref=
 +
|period comment=
 +
|block=s
 +
|block ref=
 +
|block comment=
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|electron configuration=[Ne] 3s<sup>2</sup>
 +
|electron configuration ref=
 +
|electron configuration comment=
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|electrons per shell=2, 8, 2
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|electrons per shell ref=
 +
|electrons per shell comment=
 +
<!-- Physical properties -->
 +
|physical properties comment=
 +
|color=Silvery-white
 +
|phase=Solid
 +
|phase ref=
 +
|phase comment=
 +
|melting point K=923
 +
|melting point C=650
 +
|melting point F=​1202
 +
|melting point ref=
 +
|melting point comment=
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|boiling point K=1363
 +
|boiling point C=1091
 +
|boiling point F=1994
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|boiling point ref=
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|boiling point comment=
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|sublimation point K=
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|sublimation point C=
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|sublimation point F=
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|sublimation point ref=
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|sublimation point comment=
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|density gplstp=
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|density gplstp ref=
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|density gplstp comment=
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|density gpcm3nrt=1.738
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|density gpcm3nrt ref=
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|density gpcm3nrt comment=
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|density gpcm3nrt 2=
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|density gpcm3nrt 2 ref=
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|density gpcm3nrt 2 comment=
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|density gpcm3nrt 3=
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|density gpcm3nrt 3 ref=
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|density gpcm3nrt 3 comment=
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|density gpcm3mp=1.584
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|density gpcm3mp ref=
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|density gpcm3mp comment=
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|density gpcm3bp=
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|density gpcm3bp ref=
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|density gpcm3bp comment=
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|molar volume=
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|molar volume unit =
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|molar volume ref=
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|molar volume comment=
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|triple point K=
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|triple point kPa=
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|triple point ref=
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|triple point comment=
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|triple point K 2=
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|triple point kPa 2=
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|triple point 2 ref=
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|triple point 2 comment=
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|critical point K=
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|critical point MPa=
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|critical point ref=
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|critical point comment=
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|heat fusion=8.48
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|heat fusion ref=
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|heat fusion comment=
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|heat fusion 2=
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|heat fusion 2 ref=
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|heat fusion 2 comment=
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|heat vaporization=128
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|heat vaporization ref=
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|heat vaporization comment=
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|heat capacity=24.869
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|heat capacity ref=
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|heat capacity comment=
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|heat capacity 2=
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|heat capacity 2 ref=
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|heat capacity 2 comment=
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|vapor pressure 1=701
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|vapor pressure 10=773
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|vapor pressure 100=861
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|vapor pressure 1 k=971
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|vapor pressure 10 k=1132
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|vapor pressure 100 k=1361
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|vapor pressure ref=
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|vapor pressure comment=
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|vapor pressure 1 2=
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|vapor pressure 10 2=
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|vapor pressure 100 2=
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|vapor pressure 1 k 2=
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|vapor pressure 10 k 2=
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|vapor pressure 100 k 2=
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|vapor pressure 2 ref=
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|vapor pressure 2 comment=
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<!-- Atomic properties -->
 +
|atomic properties comment=
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|oxidation states='''+2''', +1
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|oxidation states ref=
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|oxidation states comment=(a strongly basic oxide)
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|electronegativity=1.31
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|electronegativity ref=
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|electronegativity comment=
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|ionization energy 1=737.7
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|ionization energy 1 ref=
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|ionization energy 1 comment=
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|ionization energy 2=1450.7
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|ionization energy 2 ref=
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|ionization energy 2 comment=
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|ionization energy 3=7732.7
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|ionization energy 3 ref=
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|ionization energy 3 comment=
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|number of ionization energies=
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|ionization energy ref=
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|ionization energy comment=
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|atomic radius=160
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|atomic radius ref=
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|atomic radius comment=
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|atomic radius calculated=
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|atomic radius calculated ref=
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|atomic radius calculated comment=
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|covalent radius=141±7
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|covalent radius ref=
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|covalent radius comment=
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|Van der Waals radius=173
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|Van der Waals radius ref=
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|Van der Waals radius comment=
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<!-- Miscellanea -->
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|crystal structure=
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|crystal structure prefix=
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|crystal structure ref=
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|crystal structure comment= Hexagonal close-packed (hcp)
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|crystal structure 2=
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|crystal structure 2 prefix=
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|crystal structure 2 ref=
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|crystal structure 2 comment=
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|speed of sound=
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|speed of sound ref=
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|speed of sound comment=
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|speed of sound rod at 20=
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|speed of sound rod at 20 ref=
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|speed of sound rod at 20 comment=
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|speed of sound rod at r.t.=4940
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|speed of sound rod at r.t. ref=
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|speed of sound rod at r.t. comment=(annealed)
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|thermal expansion=
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|thermal expansion ref=
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|thermal expansion comment=
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|thermal expansion at 25=24.8
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|thermal expansion at 25 ref=
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|thermal expansion at 25 comment=
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|thermal conductivity=156
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|thermal conductivity ref=
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|thermal conductivity comment=
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|thermal conductivity 2=
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|thermal conductivity 2 ref=
 +
|thermal conductivity 2 comment=
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|thermal diffusivity=
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|thermal diffusivity ref=
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|thermal diffusivity comment=
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|electrical resistivity=
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|electrical resistivity unit prefix=
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|electrical resistivity ref=
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|electrical resistivity comment=
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|electrical resistivity at 0=
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|electrical resistivity at 0 ref=
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|electrical resistivity at 0 comment=
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|electrical resistivity at 20=4.39·10<sup>-8</sup>
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|electrical resistivity at 20 ref=
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|electrical resistivity at 20 comment=
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|band gap=
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|band gap ref=
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|band gap comment=
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|Curie point K=
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|Curie point ref=
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|Curie point comment=
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|magnetic ordering=Paramagnetic
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|magnetic ordering ref=
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|magnetic ordering comment=
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|tensile strength=
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|tensile strength ref=
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|tensile strength comment=
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|Young's modulus=45
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|Young's modulus ref=
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|Young's modulus comment=
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|Shear modulus=17
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|Shear modulus ref=
 +
|Shear modulus comment=
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|Bulk modulus=45
 +
|Bulk modulus ref=
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|Bulk modulus comment=
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|Poisson ratio=0.29
 +
|Poisson ratio ref=
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|Poisson ratio comment=
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|Mohs hardness=1–2.5
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|Mohs hardness ref=
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|Mohs hardness comment=
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|Mohs hardness 2=
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|Mohs hardness 2 ref=
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|Mohs hardness 2 comment=
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|Vickers hardness=
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|Vickers hardness ref=
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|Vickers hardness comment=
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|Brinell hardness=44–260
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|Brinell hardness ref=
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|Brinell hardness comment=
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|CAS number=7439-95-4
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|CAS number ref=
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|CAS number comment=
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<!-- History -->
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|naming=After Magnesia, Greece
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|predicted by=
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|prediction date ref=
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|prediction date=
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|discovered by= Joseph Black
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|discovery date ref=
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|discovery date=1755
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|first isolation by= Humphry Davy
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|first isolation date ref=
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|first isolation date=1808
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|discovery and first isolation by=
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|named by=
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|named date ref=
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|named date=
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|history comment label=
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|history comment=
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<!-- Isotopes -->
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|isotopes=
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|isotopes comment=
 +
|engvar=
 +
}}
 +
'''Magnesium''' is an [[alkaline earth metal]] with the symbol '''Mg''' and atomic number 12. It is one of the most powerful [[reducer|reducing agent]]s available to the amateur chemist, even more so than [[zinc]]. However, it is impossible to plate magnesium out of an aqueous solution, and it is generally not feasible to recover the metal.
  
 
==Properties==
 
==Properties==
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===Chemical properties===
 
===Chemical properties===
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Magnesium is an extremely powerful reducing agent, though it is relatively stable in air due to the formation of a partial passivation layer. When stored in air, magnesium will slowly oxidize, so it is advisable to store it in a sealed container. In water, magnesium pieces react only slowly to form [[magnesium hydroxide]]. It does not react with alkali solutions. However, the metal will react vigorously in dilute acids to form corresponding magnesium salts. Most of these are soluble except for the hydroxide, fluoride, and carbonate. In air, magnesium will ignite with a very hot white flame to form a mixture that consists mostly of magnesium oxide, but also contains some [[magnesium nitride]]. The color of the flame is a noticeably purer white than that of [[titanium]] or [[zirconium]] flames, which appear slightly yellowish.
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Magnesium is an extremely powerful reducing agent, though it is relatively stable in air due to the formation of a partial passivation layer. In air, magnesium will ignite with a very hot white flame to form a mixture that consists mostly of magnesium oxide, but also contains some [[magnesium nitride]].
 +
 
 +
: 2 Mg + O<sub>2</sub> → 2 MgO
 +
: 3 Mg + N<sub>2</sub> → Mg<sub>3</sub>N<sub>2</sub>
 +
 
 +
The color of the flame is a noticeably purer white than that of [[titanium]] or [[zirconium]] flames, which appear slightly yellowish. Dangerous amounts of UV light is produced when magnesium burns, necessitating eye protection if one were to stare directly at the flame.
 +
 
 +
Magnesium reacts with [[carbon dioxide]] exothermically to form [[magnesium oxide]] and [[carbon]]:
 +
 
 +
: 2 Mg + CO<sub>2</sub> → 2 MgO + C
 +
 
 +
Hence, carbon dioxide fuels rather than extinguishes magnesium fires.
 +
 
 +
Powdered Mg reacts with [[hydrogen]] at high pressure and temperature (200 atmospheres, 500 °C), in the presence of magnesium iodide catalyst, to yield magnesium hydride.
 +
 
 +
In water, magnesium pieces react only slowly to form [[magnesium hydroxide]], due to the build-up of magnesium hydroxide on the surface of the pure magnesium metal, which slows down any further reaction. Powdered magnesium, however, reacts much more vigorously with water.
 +
 
 +
: Mg + 2 H<sub>2</sub>O → Mg(OH)<sub>2</sub> + H<sub>2</sub>
 +
 
 +
Magnesium metal does not react with alkali solutions. However, the metal will react vigorously in dilute acids to form corresponding magnesium salts.
 +
 
 +
: Mg + 2 HX → MgX<sub>2</sub> + H<sub>2</sub>
 +
 
 +
Most of these are soluble except for the hydroxide, fluoride, and carbonate.
 +
 
 +
Magnesium is the choice reducing agent when extracting lanthanide metals from their salts, as well as many transition metals that cannot be extracted via carbon thermoreduction. Magnesium metal can also be used to obtain alkali metals, like sodium, potassium and even rubidium and caesium (but not lithium) by reducing their respective hydroxide, either in a [[Thermochemical dioxane approach|thermoreduction process]] or by [[Alcohol catalyzed alkali metal production|stirring the Mg-MOH mixture in an inert solvent with a tertiary alcohol as catalyst at high temperature for several hours or days]].
  
 
==Availability and sources==
 
==Availability and sources==
−
Magnesium powder can be purchased from [http://www.ebay.com/bhp/magnesium-powder eBay], at varying prices, depending on the particle size.
+
A good and readily available source of magnesium is the sacrificial anodes used in many water heaters. They can be cheaply found at most plumbing stores. One rod generally has around 200 g of magnesium metal and costs around 8-12 $.
  
 
Fire starting kits often contain magnesium of 95% purity, which is sufficient for most simple reductions.
 
Fire starting kits often contain magnesium of 95% purity, which is sufficient for most simple reductions.
  
−
Some pencil sharpeners, such as those manufactured by [http://www.cultpens.com/c/q/brands/kum KUM] and [http://www.staedtler.com/en/products/pencils-accessories/sharpeners/ Staedtler] are made of magnesium, in case of the latter, 95% pure. A simple test to see if these are made of magnesium or not involves heating one in a blowtorch flame for about 30 seconds (outside!); if it is magnesium, it will catch fire and give off intense white light. These can be found at University of California campuses. They are easily identifiable by their light weight.
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Some pencil sharpeners, such as those manufactured by [http://www.cultpens.com/c/q/brands/kum KUM] and [http://www.staedtler.com/en/products/pencils-accessories/sharpeners/ Staedtler] are made of magnesium, in case of the latter, 95% pure. A simple test to see if these are made of magnesium or not involves heating one in a blowtorch flame for about 30 seconds (outside!); if it is magnesium, it will catch fire and give off intense white light. A less destructive method involves adding a few drops of aqueous NaOH on the sharpener surface. Magnesium does not react with sodium hydroxide, but aluminium will. These can also be found at University of California campuses. They are easily identifiable by their light weight.
  
 
Magnesium products of higher purity can be bought from [http://www.mcssl.com/store/gallium-source/magnesium-metal GalliumSource]. It is sold as turnings (coarse and fine), ribbon, ingots, rods, and foil.
 
Magnesium products of higher purity can be bought from [http://www.mcssl.com/store/gallium-source/magnesium-metal GalliumSource]. It is sold as turnings (coarse and fine), ribbon, ingots, rods, and foil.
  
−
Magnesium strips can be bought from [http://unitednuclear.com/index.php?main_page=product_info&cPath=89&products_id=160 United Nuclear].
+
Magnesium strips can also be bought from [http://unitednuclear.com/index.php?main_page=product_info&cPath=89&products_id=160 United Nuclear] if you live in the US.
 +
 
 +
Magnesium powder can be purchased from [http://www.ebay.com/bhp/magnesium-powder eBay], at varying prices, depending on the particle size. In the EU, there are some restrictions regarding the sale and ownership of magnesium powders below a certain size, though there aren't any restrictions for coarse powders and turnings. Grignard-grade Mg turnings can also be bought freely from suppliers or online.
 +
 
 +
Some old laptops contain frames made out of magnesium or magnesium alloy.
  
 
==Preparation==
 
==Preparation==
−
Elemental magnesium is difficult to prepare, due to it's high reactivity. The industrial method involves the electrolysis of molten [[magnesium chloride]] or an eutectic mixture of MgCl<sub>2</sub> and KCl (melting point 450°C), in a Downs cell. This process requires the use of corrosion resistant alloy crucibles, as molten magnesium chloride is very corrosive. The process takes place in an inert atmosphere, either [[argon]] or more often [[sulfur hexafluoride]].
+
Elemental magnesium is difficult to prepare, due to its high reactivity. The industrial method involves the electrolysis of molten [[magnesium chloride]] or an eutectic mixture of MgCl<sub>2</sub> and KCl (melting point 450 °C), in a Downs cell. This process requires the use of corrosion-resistant alloy crucibles, as molten magnesium chloride is very corrosive. The process takes place in an inert atmosphere, either [[argon]] or more often [[sulfur hexafluoride]].
  
 
==Projects==
 
==Projects==
 
*Make [[flash powder]] (water sensitive)
 
*Make [[flash powder]] (water sensitive)
−
*Make [[thermite]]
+
*Make and ignite [[thermite]]
 
*Grignard reactions
 
*Grignard reactions
−
*Make [[potassium]] metal
+
*Make [[sodium]] and [[potassium]] metal
  
 
==Handling==
 
==Handling==
 
===Safety===
 
===Safety===
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Magnesium and its compounds are not particularly toxic. Bulk magnesium is not prone to ignition, but magnesium powder and turnings are. '''Water and Carbon Dioxide extinguishers must NEVER be used to put out magnesium fires, as this accelerates the burning and can produce toxic and/or explosive gasses as a byproduct.  Dry sand can be used to fight burning magnesium.'''
+
Magnesium and its compounds are not particularly toxic. Bulk magnesium is not prone to ignition, but magnesium powder and turnings are. '''Water and Carbon Dioxide extinguishers must NEVER be used to put out magnesium fires''', as this accelerates the burning and can produce toxic and/or explosive gasses as a byproduct.  Dry sand can be used to fight burning magnesium. Likewise, powdered magnesium oxide aka magnesia is also suitable for putting out magnesium fires.
  
 
'''Never consume magnesium or its compounds, when produced in the laboratory, as a supplement.'''
 
'''Never consume magnesium or its compounds, when produced in the laboratory, as a supplement.'''
  
 
===Storage===
 
===Storage===
−
Magnesium metal will slowly corrode in air and turn dark gray. To prevent this, storage under [[mineral oil]] is sufficient. For long-term storage, [[Ampoule|ampouling]] is a viable solution, though rarely necessary.
+
Magnesium metal will slowly corrode in air and turn dark gray. To prevent this, storage under [[mineral oil]] is sufficient. For long-term storage, [[Ampoule|ampouling]] is a viable solution, though rarely necessary. Keep it away from acidic vapors and corrosive gases.
 +
 
 +
In general, magnesium doesn't require special storage conditions, as long as the air from the storage space has low humidity and is not polluted. A simple zip lock bag is good enough to keep magnesium unaffected for several years.
  
 
===Disposal===
 
===Disposal===
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<references/>
 
<references/>
 
===Relevant Sciencemadness threads===
 
===Relevant Sciencemadness threads===
 +
*[http://www.sciencemadness.org/talk/viewthread.php?tid=134874 How to discover if something is made of Magnesium?]
 
*[http://www.sciencemadness.org/talk/viewthread.php?tid=15555 Why are pencil sharpners magnesium?]
 
*[http://www.sciencemadness.org/talk/viewthread.php?tid=15555 Why are pencil sharpners magnesium?]
 +
*[http://www.sciencemadness.org/talk/viewthread.php?tid=29857 Magnesium Metal from scrapyard]
 +
*[http://www.sciencemadness.org/talk/viewthread.php?tid=74617 Cheap/Easy Sources of Magnesium Metal]
 +
*[http://www.sciencemadness.org/talk/viewthread.php?tid=4617 Magnesium metal in Italy?]
 +
*[http://www.sciencemadness.org/talk/viewthread.php?tid=16637 Magnesium powder from magnesium ingots]
 +
*[http://www.sciencemadness.org/talk/viewthread.php?tid=14238 Magnesium powder from magnesium pencil sharpener]
 +
*[http://www.sciencemadness.org/talk/viewthread.php?tid=15338 Are Magnesium Metal Flakes Spontaneously Reactive with Any Oxidizers?]
 +
*[http://www.sciencemadness.org/talk/viewthread.php?tid=14 Extracting magnesium metal from its salts]
 
*[http://www.sciencemadness.org/talk/viewthread.php?tid=8757 Mg metal from MgO]
 
*[http://www.sciencemadness.org/talk/viewthread.php?tid=8757 Mg metal from MgO]
 +
*[http://www.sciencemadness.org/talk/viewthread.php?tid=97625 Electrolysis of MgCl2 (a realistic objective?)]
  
 
[[Category:Elements]]
 
[[Category:Elements]]

Latest revision as of 18:21, 27 February 2024

Magnesium,  12Mg
Magnesium ribbon.jpg
Magnesium ribbon stored in mineral oil to prevent oxidation
General properties
Name, symbol Magnesium, Mg
Appearance Silvery-white
Magnesium in the periodic table
Be
↑
Mg
↓
Ca
Sodium ← Magnesium → Aluminium
Atomic number 12
Standard atomic weight (Ar) 24.305
Group, block 2 (alkaline earth metals); s-block
Period period 3
Electron configuration [Ne] 3s2
per shell
 2, 8, 2
Physical properties
Silvery-white
Phase Solid
Melting point 923 K ​(650 °C, ​​1202 °F)
Boiling point 1363 K ​(1091 °C, ​1994 °F)
Density near r.t. 1.738 g/cm3
when liquid, at  1.584 g/cm3
Heat of fusion 8.48 kJ/mol
Heat of 128 kJ/mol
Molar heat capacity 24.869 J/(mol·K)
 pressure
Atomic properties
Oxidation states +2, +1 ​(a strongly basic oxide)
Electronegativity Pauling scale: 1.31
energies 1st: 737.7 kJ/mol
2nd: 1450.7 kJ/mol
3rd: 7732.7 kJ/mol
Atomic radius empirical: 160 pm
Covalent radius 141±7 pm
Van der Waals radius 173 pm
Miscellanea
Crystal structure ​Hexagonal close-packed (hcp)
Speed of sound thin rod 4940 m/s (at ) (annealed)
Thermal expansion 24.8 µm/(m·K) (at 25 °C)
Thermal conductivity 156 W/(m·K)
Electrical resistivity 4.39·10-8 Ω·m (at 20 °C)
Magnetic ordering Paramagnetic
Young's modulus 45 GPa
Shear modulus 17 GPa
Bulk modulus 45 GPa
Poisson ratio 0.29
Mohs hardness 1–2.5
Brinell hardness 44–260 MPa
CAS Registry Number 7439-95-4
History
Naming After Magnesia, Greece
Discovery Joseph Black (1755)
First isolation Humphry Davy (1808)
· references

Magnesium is an alkaline earth metal with the symbol Mg and atomic number 12. It is one of the most powerful reducing agents available to the amateur chemist, even more so than zinc. However, it is impossible to plate magnesium out of an aqueous solution, and it is generally not feasible to recover the metal.

Properties

Physical properties

Magnesium is a light, grayish metal. Oxidized pieces are a darker shade of gray, and tend to have a white powder of magnesium oxide on the surface. It has a low melting point of 650 °C, though the metal will ignite in air before it reaches that temperature.

Chemical properties

Magnesium is an extremely powerful reducing agent, though it is relatively stable in air due to the formation of a partial passivation layer. In air, magnesium will ignite with a very hot white flame to form a mixture that consists mostly of magnesium oxide, but also contains some magnesium nitride.

2 Mg + O2 → 2 MgO
3 Mg + N2 → Mg3N2

The color of the flame is a noticeably purer white than that of titanium or zirconium flames, which appear slightly yellowish. Dangerous amounts of UV light is produced when magnesium burns, necessitating eye protection if one were to stare directly at the flame.

Magnesium reacts with carbon dioxide exothermically to form magnesium oxide and carbon:

2 Mg + CO2 → 2 MgO + C

Hence, carbon dioxide fuels rather than extinguishes magnesium fires.

Powdered Mg reacts with hydrogen at high pressure and temperature (200 atmospheres, 500 °C), in the presence of magnesium iodide catalyst, to yield magnesium hydride.

In water, magnesium pieces react only slowly to form magnesium hydroxide, due to the build-up of magnesium hydroxide on the surface of the pure magnesium metal, which slows down any further reaction. Powdered magnesium, however, reacts much more vigorously with water.

Mg + 2 H2O → Mg(OH)2 + H2

Magnesium metal does not react with alkali solutions. However, the metal will react vigorously in dilute acids to form corresponding magnesium salts.

Mg + 2 HX → MgX2 + H2

Most of these are soluble except for the hydroxide, fluoride, and carbonate.

Magnesium is the choice reducing agent when extracting lanthanide metals from their salts, as well as many transition metals that cannot be extracted via carbon thermoreduction. Magnesium metal can also be used to obtain alkali metals, like sodium, potassium and even rubidium and caesium (but not lithium) by reducing their respective hydroxide, either in a thermoreduction process or by stirring the Mg-MOH mixture in an inert solvent with a tertiary alcohol as catalyst at high temperature for several hours or days.

Availability and sources

A good and readily available source of magnesium is the sacrificial anodes used in many water heaters. They can be cheaply found at most plumbing stores. One rod generally has around 200 g of magnesium metal and costs around 8-12 $.

Fire starting kits often contain magnesium of 95% purity, which is sufficient for most simple reductions.

Some pencil sharpeners, such as those manufactured by KUM and Staedtler are made of magnesium, in case of the latter, 95% pure. A simple test to see if these are made of magnesium or not involves heating one in a blowtorch flame for about 30 seconds (outside!); if it is magnesium, it will catch fire and give off intense white light. A less destructive method involves adding a few drops of aqueous NaOH on the sharpener surface. Magnesium does not react with sodium hydroxide, but aluminium will. These can also be found at University of California campuses. They are easily identifiable by their light weight.

Magnesium products of higher purity can be bought from GalliumSource. It is sold as turnings (coarse and fine), ribbon, ingots, rods, and foil.

Magnesium strips can also be bought from United Nuclear if you live in the US.

Magnesium powder can be purchased from eBay, at varying prices, depending on the particle size. In the EU, there are some restrictions regarding the sale and ownership of magnesium powders below a certain size, though there aren't any restrictions for coarse powders and turnings. Grignard-grade Mg turnings can also be bought freely from suppliers or online.

Some old laptops contain frames made out of magnesium or magnesium alloy.

Preparation

Elemental magnesium is difficult to prepare, due to its high reactivity. The industrial method involves the electrolysis of molten magnesium chloride or an eutectic mixture of MgCl2 and KCl (melting point 450 °C), in a Downs cell. This process requires the use of corrosion-resistant alloy crucibles, as molten magnesium chloride is very corrosive. The process takes place in an inert atmosphere, either argon or more often sulfur hexafluoride.

Projects

Handling

Safety

Magnesium and its compounds are not particularly toxic. Bulk magnesium is not prone to ignition, but magnesium powder and turnings are. Water and Carbon Dioxide extinguishers must NEVER be used to put out magnesium fires, as this accelerates the burning and can produce toxic and/or explosive gasses as a byproduct. Dry sand can be used to fight burning magnesium. Likewise, powdered magnesium oxide aka magnesia is also suitable for putting out magnesium fires.

Never consume magnesium or its compounds, when produced in the laboratory, as a supplement.

Storage

Magnesium metal will slowly corrode in air and turn dark gray. To prevent this, storage under mineral oil is sufficient. For long-term storage, ampouling is a viable solution, though rarely necessary. Keep it away from acidic vapors and corrosive gases.

In general, magnesium doesn't require special storage conditions, as long as the air from the storage space has low humidity and is not polluted. A simple zip lock bag is good enough to keep magnesium unaffected for several years.

Disposal

No special disposal procedures are required for magnesium and magnesium compounds. Discard them as you wish.

References

Relevant Sciencemadness threads

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